The present invention relates, in general, to a machine for installing a catenary cable formed by a contact wire or a carrying cable of an electrical catenary of a track, and more particularly but not exclusively to a machine of a type comprising a machine frame extending in a longitudinal direction and supported for mobility on the track by undercarriages, and a storage drum containing the rolled-up catenary cable which is pulled off the storage drum during installation with a pull-off force. A deflection roller is mounted for vertical adjustment for guiding the catenary cable during installation. An auxiliary frame is mounted on the machine frame for supporting the storage drum, and a friction winch is provided for creating a pull-off resistance counteracting the pull-off force when the catenary cable is pulled off the storage drum during installation, thus producing an installation tension, the friction winch being arranged between the storage drum and the deflection roller.
European Patent No. 0 416 136 B1 discloses a machine of this type including a force sensor for measuring the installation tension, the sensor being positioned between the friction winch and the deflection roller. This known arrangement has the disadvantage, however, that increased or additional manipulation is required each time a storage drum is to be exchanged. Furthermore, the force sensor needs to be readjusted when a switch is made from contact wire to carrying cable or vice versa, or when wires of different cross-section are being installed.
It would be desirable and advantageous to provide an improved machine of the afore-described type, with which it is possible to accurately detect the installation tension of the catenary cable while at the same time avoiding time-consuming retooling or adjusting operations.